Need help when repackaging PNP Driver

I need some help, because I've got some trouble when install my msi package.
I've follow some tutorials but result is always the same. Actually I used Device Driver template (in Wise for Windows Installer 6.10) with merge module DiffxApp

First I've created a folder (in Program Files) to store drivers files (.inf, cat, dll, exe, sys)
Then I've added file (the first was .inf file, in order to become component keypath)
When all file was in the folder, I've edited 'Details' about .inf file. Select 'Driver' tab, and then check 'Use DiffxApp to install this driver file'. I've also checked the three other box.

Sorry but I was wrong in my last post. In fact, when I try to install with the method given by VBScab, install failed.
If someone has an idea to identify which parameter is incorrect, it would be nice.

One more time I need your help because I have some troubles during repackaging drivers.

I have to uninstall previous version of the driver (6.14.XX.48.31) and then install new (6.14.XX.49.26). Uninstall is ok but ask for reboot. As I have set my custom action to ignore exit code, package continues his installation and try to install the new driver. Here is the problem : in fact, DPInst.exe cannot install the new driver. I have found in DPInst.log these lines :

INFO: Installing INF file "C:\WINNT\system32\DRVSTORE\kit12928_7A98A40EC8A4E16D6B66C417F29520B781AADAB4\kit12928.inf" of Type 6.
INFO: Looking for Model Section [Intel.Mfg]...
INFO: Installing devices with Id "PCI\VEN_8086&DEV_2A02&SUBSYS_01F91028&REV_0C" using INF "C:\WINNT\system32\DRVSTORE\kit12928_7A98A40EC8A4E16D6B66C417F29520B781AADAB4\kit12928.inf".
INFO: Installation did not occur because the current driver on the device is the same or better.
INFO: Installing devices with Id "PCI\VEN_8086&DEV_2A03&SUBSYS_01F91028&REV_0C" using INF "C:\WINNT\system32\DRVSTORE\kit12928_7A98A40EC8A4E16D6B66C417F29520B781AADAB4\kit12928.inf".
INFO: Installation did not occur because the current driver on the device is the same or better.
INFO: No drivers installed. Drivers contained in 'C:\WINNT\system32\DRVSTORE\kit12928_7A98A40EC8A4E16D6B66C417F29520B781AADAB4\kit12928.inf' are not better than current one's.
SUCCESS:Installation completed with code 0x103.
INFO: RETURN: DriverPackageInstallW (0x103)
INFO: Did not install 'c:\program files\delld630video\kit12928.inf' because it is not better than the current drivers.

As you can see, it says that drivers cannot be installed because new driver is not better than old. Did you know how is performing the comparison ?

Another way is to schedule reboot between uninstall old driver and reinstall new. is it possible ?